A police sketch of Bangkok bomber suspectPolice handoutThailand's police arrested a suspect over a bombing in Bangkok after releasing these sketches.Bangkok police department

Thailand's authorities said they have arrested the main suspect over a deadly bombing at a Bangkok shrine in August. Prime minister Prayut Chan-o-cha said the man, a foreign national, was captured as he was trying to cross into Cambodia.

Prayut, the head of the military junta ruling the country, said detectives are convinced the suspect is the same man in a yellow shirt who was filmed by a security camera leaving a backpack at the site of the August 17 explosion, the Bangkok Post reported. "We are interrogating. He is a main suspect and a foreigner," the general was quoted as saying.

The man's name and nationality have not been revealed. He was held at a border crossing near Aranyaprathet, eastern Thailand. The development came after another man suspected of involvement in the attack at Erawan Shrine that left 20 people dead was arrested at a flat in the capital at the weekend. Police found explosives and numerous travel documents, including a fake Turkish passport as they raided the premises.

The 28-year-old, whose nationality and name have also not yet been established, although he is also said to be a foreign national, reportedly gave authorities the names of several accomplices. Police subsequently released detailed sketches of a man named only as Jusuf and a 26-year-old Thai woman identified as Wanna Suansun.

Motives for the attack at the popular tourist attraction remain unclear. No one has claimed responsibility for it but authorities said the suspected bomber was part of a wider network. Fingers have been pointed at Uighur militants from north-western China, and Islamists from Indonesia, but no conclusive evidence has so far emerged.